JP2965753B2 - Exposure equipment for electrophotographic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus for an electrophotographic apparatus for exposing a surface of a photoreceptor to image light in the electrophotographic apparatus.

2. Description of the Related Art In an electrophotographic apparatus, an apparatus which scans a surface of a photosensitive member with a semiconductor laser beam is widely used.

[0003]

2. Description of the Related Art Generally, an exposure apparatus of an electrophotographic apparatus generally includes a laser diode for generating and emitting a semiconductor laser beam, a lens for converging the laser beam on the surface of a photoreceptor, and a laser beam for converging the laser beam on the surface of the photoreceptor. A common mirror is provided with a polygon mirror for performing horizontal scanning and a scanning reference position detection sensor for detecting a reference position serving as a starting point of the scanning range. After finely adjusting the positional relationship between the scanning reference position detection sensor and the laser beam, the frame is fixed to the main body of the electrophotographic apparatus.

[0004]

However, when the frame is fixed to the main body of the electrophotographic apparatus after the positional relationship between the scanning reference position detection sensor and the laser beam is finely adjusted, the screw tightening force becomes uneven or fixed. The frame is distorted due to the generated stress or the like, and as a result, the positional relationship between the scanning reference position detection sensor and the laser beam is deviated. In some cases, the quality of the electrostatic latent image was degraded.

SUMMARY OF THE INVENTION The present invention provides an exposure apparatus for an electrophotographic apparatus capable of performing accurate scanning by ensuring that a scanning reference position detection sensor and a laser beam have a correct positional relationship without deviation. With the goal.

[0006]

In order to achieve the above object, an exposure apparatus for an electrophotographic apparatus according to the present invention comprises a charged photosensitive member 1 as shown in FIG.
A laser beam emitting unit 31 for exposing the laser beam, a beam scanning unit 32 for scanning the laser beam emitted from the laser beam emitting unit 31 on the surface of the photoreceptor 1, and scanning by the beam scanning unit 32 In order to detect the reference position of the range, when the laser beam is incident, it is converted into an electric signal to output the laser reference position detection means 36, the scanning reference position detection means 36, and the laser beam incident thereon. In an exposure apparatus of an electrophotographic apparatus in which a detection position fine adjustment means 40 for fine adjustment of the positional relationship is mounted on a common frame 39, a working window 38 for fine adjustment by the detection position fine adjustment means 40 is provided.
Is provided in the frame 39.

[0007] A cover 49 for closing the work window 38 may be provided so as to be openable and closable with respect to the work window 38. The exposure apparatus of the electrophotographic apparatus according to the present invention includes a laser beam emitting unit 31 for exposing the charged photoconductor 1 and a laser beam emitted from the laser beam emitting unit 31 on the surface of the photoconductor 1. Beam scanning means 32 for scanning upward, and a scanning reference position for converting the laser beam into an electric signal and outputting it when the laser beam is incident in order to detect a reference position of a scanning range by the beam scanning means 32 A common sub-frame 60 is connected to the detecting unit 36.
And the sub-frame 60 is mounted on the main frame 59 fixed to the main body of the electrophotographic apparatus without being fixed.

[0008] In addition, a plurality of feet 6
1 may be projected downward, and the foot 61 may be placed on the bottom surface of the main frame 59.

[0009]

After fixing the frame 39 to which the parts and units such as the scanning reference position detecting means 36 are attached to the main body of the electrophotographic apparatus, a tool is inserted from the working window 38 into the detecting position fine adjusting means 40 in the frame 39. Thus, the positional relationship between the scanning reference position detecting means 36 and the laser beam incident thereon can be finely adjusted. Then, after the fine adjustment is completed, the work window 38 can be closed by the cover that can be opened and closed.

Further, if parts and units such as the scanning reference position detecting means 36 are attached to the sub-frame 60 and the sub-frame 60 is mounted on the main frame 59 without being fixed, the sub-frame 60 No distortion occurs.

Therefore, if the positional relationship between the scanning reference position detecting means 36 and the laser beam incident thereon is finely adjusted in advance on the sub-frame 60, the positional relationship is disturbed when incorporated into the main body of the electrophotographic apparatus. Does not occur.

[0012]

An embodiment will be described with reference to the drawings. FIG.
1 shows a laser beam printer to which the present invention is applied.
However, the present invention can be applied to copiers, facsimile machines, and other electrophotographic devices.

In FIG. 2, a charger 2, an exposing device 3, a developing device 4, a transfer device 5, and a cleaner 7 are arranged around the photosensitive drum 1 rotating in the direction of the arrow. Is first negatively charged by corona discharge of the charger 2.

Next, when light corresponding to an image to be recorded is applied from the exposure device 3 to the surface, the potential of the exposed portion decreases, and an electrostatic latent image is formed on the surface of the photosensitive drum 1. It is formed. When the latent image area passes through the developing device 4, the negatively charged toner (developer) adheres to the latent image area, and the toner is developed.

On the other hand, a sheet 8 on which an image is printed is supplied from a sheet hopper 9 to a position where the sheet 8 comes into contact with a toner image formed on the photosensitive drum 1 one by one. Also, the transfer device 5
Is provided on the back side of the sheet 8 below the photosensitive drum 1 so as to apply a positive charge to the sheet 8. Therefore, the toner image formed on the surface of the photosensitive drum 1 is attracted by the positive charges of the paper 8 and is transferred to the toner.

The sheet 8 onto which the toner image has been transferred is placed on the fixing device 1.
1 fixes the paper 8. The toner remaining on the surface of the photosensitive drum 1 having the toner transferred to the paper 8 is cleaned by the cleaner 7.

FIG. 1 is a plan view of an exposure apparatus according to a first embodiment of the present invention, and FIG. 3 is a partial sectional side view thereof. In the figure, 31
Denotes a laser diode for emitting a laser beam (semiconductor laser), which emits a laser beam at a timing according to an image signal input from an image processing circuit (not shown).

Reference numeral 32 denotes a polygon mirror which is a polygon mirror having a reflection surface formed on a side surface thereof. The polygon mirror 32 is driven to rotate by a motor (not shown), and the laser beam is reflected by the mirror surface, whereby the axis of the photosensitive drum 1 is rotated. The laser beam is horizontally scanned on the surface of the photosensitive drum along the direction.

Reference numerals 33 and 34 denote correction lenses which are formed wide so as to transmit a laser beam which is scanned by the polygon mirror 32 and oscillates horizontally. The laser beams are converged on the surface of the photosensitive drum 1 by the correction lenses 33 and 34. Reference numeral 35 denotes a reflection mirror that reflects the laser beam so as to irradiate the surface of the photosensitive drum 1 vertically.

Such parts and units are all formed in a box-shaped exposure apparatus frame 39 (hereinafter simply referred to as "frame 39").
The laser beam emitted from the laser diode 31 is converged and scanned on the surface of the photosensitive drum 1 to expose the photosensitive layer.

Reference numeral 36 denotes a horizontal synchronization detection sensor (scan reference position detection) for detecting the starting point of the scanning range of the laser beam scanned while being swung horizontally by the rotation of the polygon mirror 32. Means). The horizontal synchronization detection sensor 36 is screwed and fixed in a frame 39. When a laser beam enters, the light energy is converted into an electric signal and output.

Reference numeral 40 denotes a detection position finer which reflects a laser beam to be incident on the horizontal synchronization detection sensor 36 and can change the reflection angle to change the positional relationship between the horizontal synchronization detection sensor 36 and the laser beam. It is an adjustment device.

The detection position fine adjustment device 40 is provided at the start point of the scanning range, and is formed by erecting a plane mirror 42 on a rotating plate 41 placed in close contact with the floor surface of the frame 39. I have. By rotating the plane mirror 42 about the rotation axis 43, the direction of the plane mirror 42 can be changed and the reflection direction of the laser beam can be finely adjusted.

An arc-shaped long groove 44 centering on the rotating shaft 43 is formed in the rotating plate 41 so as to penetrate therethrough, and a screw screwed into the floor of the frame 39 through the long groove 44. The rotating plate 41 is fixed to the frame 39 by tightening 45.

The lid 39a of the frame 39
A work window 38 is formed at a position facing the detection position fine adjustment device 40, and a tool such as a screwdriver is inserted into the frame 39 from outside through the work window 38,
The detection position fine adjustment device 40 can be finely adjusted (that is, the screw 45 is retightened by changing the direction of the plane mirror 42 by a small angle).

Therefore, according to the above embodiment, after the frame 39 is firmly fixed to the main body of the electrophotographic apparatus, finally, the positional relationship between the horizontal synchronization detection sensor 36 and the laser beam can be finely adjusted accurately. I can do it.

It should be noted that reference numeral 49 shown in FIG.
The cover 8 is an openable / closable cover for closing the cover 8 and can be formed by, for example, an adhesive sheet or a rotating lid. After the fine adjustment is completed, the work window 38 is closed,
It is possible to prevent dust and the like from entering the inside.

FIG. 4 is a plan view of an exposure apparatus 3 according to a second embodiment of the present invention, and FIG. 5 is a partial cross-sectional side view of the same. The description is omitted.

In this embodiment, the components and units mounted on the frame 39 in the first embodiment are mounted on a flat sub-frame 60 mounted on the main frame 59.

The main frame 59 is fixedly screwed to the main body of the electrophotographic apparatus, and its floor is formed as a convex surface having a high central portion and a low peripheral portion. On the other hand, the subframe 60
, Three legs 61 project downward from the peripheral portion at an interval, and the legs 61 are placed on the floor of the main frame 59 without being fixed.

Therefore, even if the main frame 59 is slightly tilted or distorted, the sub-frame 60 is not affected by the tilt and is distorted without receiving any force from the main frame 59 side. Maintain a stable state without floating from the floor.

Therefore, if the positional relationship between the horizontal synchronization detection sensor 36 and the laser beam is adjusted to the correct state in advance, when the exposure apparatus 3 is mounted on the main body 100 of the electrophotographic apparatus, the subframe 60 will not have any distortion or the like. Does not occur and there is no need to readjust.

[0033]

According to the exposure apparatus for an electrophotographic apparatus of the present invention, by providing a working window in the frame, even after the exposure apparatus is mounted on the main body of the electrophotographic apparatus, the scanning reference position detecting means and the incident light therefrom are detected. The positional relationship with the laser beam to be adjusted can be finely adjusted by the detection position fine adjustment means, and the sub-frame on which parts and units are mounted is mounted on the main frame without being fixed, so that the exposure apparatus can be electronically mounted. Since distortion does not occur on the sub-frame side when attached to the photographic apparatus main body, the positional relationship between the scanning reference position detecting means and the laser beam does not change.

Therefore, the laser beam can be detected at the correct detection timing by the scanning reference position detecting means to perform an accurate scan, thereby performing an accurate exposure on the photosensitive member.

[Brief description of the drawings]

FIG. 1 is a plan view of a first embodiment.

FIG. 2 is a schematic side view of the electrophotographic apparatus according to the embodiment.

FIG. 3 is a partial side sectional view of the first embodiment.

FIG. 4 is a plan view of a second embodiment.

FIG. 5 is a partial side sectional view of the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photosensitive drum (photosensitive body) 31 Laser diode (laser beam emitting means) 32 Polygon mirror (beam scanning means) 36 Horizontal synchronization detecting sensor (scanning reference position detecting means) 38 Working window 39 Frame 40 Detection position fine adjustment device (detection) Position fine adjustment means) 59 Main frame 60 Sub frame

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takeo Kojima Inside Fujitsu Limited, 1015 Ueodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture 58) Surveyed field (Int.Cl. ⁶ , DB name) G02B 26/10

Claims (4)

(57) [Claims] 1. A laser beam emitting means (31) for exposing a charged photoconductor (1), and a laser beam emitted from the laser beam emitting means (31) is applied to a surface of the photoconductor (1). Beam scanning means (32) for scanning upward; and, in order to detect a reference position of a scanning range of the beam scanning means (32), when the laser beam is incident, the laser beam is converted into an electric signal and output. A scanning reference position detecting means (36), and a detecting position fine adjusting means (40) for finely adjusting the positional relationship between the scanning reference position detecting means (36) and the laser beam incident thereon. 39. In the exposure apparatus of the electrophotographic apparatus attached to 39), a working window (38) for fine adjustment by the detection position fine adjustment means (40) is perforated in the frame (39). An exposure apparatus for an electrophotographic apparatus, comprising: 2. An exposure apparatus for an electrophotographic apparatus according to claim 1, wherein a cover (49) for closing said work window (38) is provided so as to be openable and closable with respect to said work window (38). 3. A laser beam emitting means (31) for exposing a charged photoconductor (1), and a laser beam emitted from the laser beam emitting means (31) is applied to the surface of the photoconductor (1). Beam scanning means (32) for scanning upward; and, in order to detect a reference position of a scanning range of the beam scanning means (32), when the laser beam is incident, the laser beam is converted into an electric signal and output. The scanning reference position detecting means (36) is attached to the common sub-frame (60), and the main frame (5) fixed to the main body of the electrophotographic apparatus.
An exposure apparatus for an electrophotographic apparatus, wherein the sub-frame (60) is mounted without fixing to (9). 4. The sub-frame (60) has a plurality of feet (61) projecting downward, and the feet (61) are mounted on the bottom surface of the main frame (59). 4. An exposure apparatus for an electrophotographic apparatus according to 3.